Composition for explosives comprising an alloy of magnesium and cerium

ABSTRACT

COMPOSITION OF MATTER SUITABLE FOR USE AS AN EXPLOSIVE PRIMER OR NOISEMAKER COMPRISING: (A) 20-70 WT. PERCENT OF AN ALLOY OF CERIUM AND MAGNESIUM IN THE PROPORTION OF CERIUM TO MAGNESIUM OF 4:6 TO 8.5:1.5. (B) 80-30 WT. PERCENT OF AN INORGANIC OXIDIZER FOR EXPLOSIVES.

United States Patent 3,671,343 COMPOSITION FOR EXPLOSIV ES COMPRISING AN ALLOY OF MAGNESIUM AND CERIUM Heinz Gawlick, Furth, Bavaria, Gunther Marondel, Erlangen, and Werner Siegelin, Stein bei Nurnberg, Germany, assignors to Dynamit Nobel Aktiengcsellschaft, Troisdorf, Germany No Drawing. Filed Oct. 31, 1969, Ser. No. 873,108 Claims priority, application Germany, Nov. 2, 1968, P 18 06 548.0 Int. Cl. C06b 15/00 US. Cl. 149-37 13 Claims ABSTRACT OF THE DISCLOSURE Composition of matter suitable for use as an explosive primer or noisemaker comprising:

(a) 20-70 wt. percent of an alloy of cerium and magnesium in the proportion of cerium to magnesium of 4:6 to 8.5:1.5. (b)' 80-30 wt. percent of an inorganic oxidizer for explosives.

BACKGROUND The initiation of brisant explosives is commonly brought about by means of blasting caps or priming pellet mixtures. Blasting caps contain as the explosive mainly lead azide, which in turn causes the reaction of a nitro compound, 64g. tetryl, which is also contained in the cap, as a booster charge.

These blasting caps are very sensitive to mechanical stress and therefore have to be handled with special caution. If improperly handled, such blasting caps can therefore detonate accidentally.

The detonation of brisant explosives by means of a priming pellet mixture is based on the thermal shock produced by this mixture, which consists preferably of aluminum and barium peroxide. The use of priming pellets, however, has the disadvantage that, for many applications, they take too long to start the detonation, requiring as much as several tenths of a second.

THE INVENTION A priming and noisemaking composition has now been found which comprises or consists essentially of 20 to 70 wt. percent, preferably 35-5-5 wt. percent, of a cerium magnesium alloy and 80 to 30 wt. percent, preferably 65- 45 wt. percent, of aninorganic oxidizer which yields oxygen easily. The composition is markedly insensitive to shock and friction.

Such a composition, which can be used in either the pressed or the unpressed state as a priming composition, brings a brisant explosive to detonation within 20 to 160 milliseconds, the term brisant explosive being understood to mean an explosive whose rate of detonation is greater than 5000 m./sec., such as PETN (pentaerythrite tetranitrate), nitromannite, or other explosive nitroesters of sugar alcohols. The composition does not have the high sensitivity of the blasting caps mentioned above.

The weight ratio of cerium to magnesium in the cerium magnesium alloys ranges from 4:6 and 8.5:1.5. In the priming compositions it can range between 624 and 8.5 1.5, and preferably between 7:3 and 8 :2, in the noisemaking (firecracker) composition it can range between 4:6 and 8:2, preferably between :5 and 6:4. The cerium magnesium alloy can. comprise or consist of 6075 wt. percent cerium and 40-25 wt. percent magnesium.

Inorganic compounds which easily yield oxygen suitable for the purposes of the invention are the inorganic oxygen compounds known in the art as oxygen suppliers.

3,671,343 Patented June 20, 1972 Oxides of heavy metals in the highest oxidation stage which forms a solid, stable oxide are suitable. Examples are 0110, PbO However, heavy metal oxides which decompose to a still lower oxidation stage can be used according to the invention, such as MnO' for example.

Furthermore, the alkali salts, alkaline earth salts, and ammonia salts of chromic and permanganic acid are also to be considered according to the invention as inorganic compounds which easily yield oxygen, examples being ammonium dichromate or potassium permanganate.

The oxidizing agent and the cerium magnesium alloy preferably have such a fineness of grain that 100% will pass through a sieve having a mesh width of 0.1 mm.

The mixing of the components of the priming composition is performed in a conventional manner. The mixture can be used for initiation either in the pressed or unpressed state. It is desirable to press it onto thebrisant explosive that is to be initiated. A quantity amounting, for example, to 40 mg. of the mixture will suffice to initiate 100 mg. of PETN or nitromannite.

Example 1 4 grams of a cerium magnesium alloy consisting of cerium and 20% magnesium by weight, and having a grain size of 100% less than 0.1 mm., was intimately mixed with 6 g. of powdered lead dioxide (grain size 100% less than 0.1 mm.). Then about three grams of this mixture was pressed into a blasting cap containing 8 g. of PETN as a booster charge in the conventional manner. The charge was ignited with a primer and the blasting cap detonated within 80 milliseconds, approximately.

Example 2 3 grams of finely powdered cerium magnesium alloy (grain size 100% less than 0.1 mm.) with 2 grams of 50% magnesium and 50% cerium was intimately mixed with finely powdered potassium permanganate (grain size 100% less than 0.1 mm). Approximately one quarter of the mixture was ignited by an incandescent flame of a bunsen burner. The charge reacted with a very loud report.

What is claimed is:

1. Composition of matter suitable for use as an ex plosive primer or noisemaker comprising:

(a) 20-70 wt. percent of an alloy of cerium and magnesium in the proportion of cerium to magnesium of 4:6 to 8.5215.

(b) 80-30 wt. percent of an inorganic oxidizer for explosives.

2. Composition according to claim 1, said inorganic oxidizer being PbO CuO, or a mixture thereof.

3 Composition according to claim 1, said inorganic oxidizer comprising potassium permanganate.

4. Composition according to claim 1, the alloy of cerium and magnesium being in the proportion of cerium to magnesium of 6:4 to :15.

5. Composition according to claim 1, the alloy of cerium and magnesium being in the proportion of cerium to magnesium of 7:3 to 8:2.

6. Composition according to claim 1, the alloy of cerium and magnesium being in the proportion of cerium to magnesium of 4:6 to 8:2.

7. Composition according to claim 1, the alloy of cerium and magnesium being in the proportion of cerium to magnesium of 5:5 to 6:4.

8. Explosives comprising as a principal component a brisant composition and as a primer therefor, an explosive primer composition according to claim 1.

9. Explosive comprising as a principal component a brisant composition and as a primer therefor, an explosive primer composition according to claim 4.

10. Explosive comprising as a principal component a bn'sant composition and as a primer therefor, an explosive primer composition according to claim 5.

11. Explosive comprising as a principal component a brisant composition of the group pentaerythrite tetranitrate, nitromannite, and explosive nitroesters of sugar alcohols, and as a primer therefor, an explosive primer composition according to claim 1.

12. Explosive comprising as a principal component a brisant composition of the group pentaerythrite tetranitrate, nitromannite, and explosive nitroesters of sugar alcohols, and as a primer therefor, an explosive primer composition according to claim 4.

13. Explosive comprising as a principal component a brisant composition of the group pentaerythrite tetranitrate, nitromannite, and explosive nitroesters of sugar alcohols, and as a primer therefor, an explosive primer composition according to claim 5.

CARL D. QUARFORTH, Primary Examiner S. J. LECI-IERT, JR, Assistant Examiner US. Cl. X. R. 

